Spin-polarised transport and evidence for novel spin valve behavior in YBCO/LSMO/YBCO hybrid structures

Anisotropic RBa2Cu3O7-σ high temperature superconductors (RBCO), where R represents the rare earth elements Y, Nd and Pr, as well as the layered manganite La2/3Sr1/3MnO3 (LSMO), are layered metallic systems where the interlayer current transport occurs via sequential tunneling of charge carriers. We present here experimental results of interlayer spin polarized transport studies carried out on YBa2Cu3O7-σ/La2/3Sr1/3MnO3/YBa2Cu3O7-σ thin film multilayers. The tunneling of spin polarized charge carriers between the YBCO layers through LSMO leads to a novel spin valve effects at high temperatures. Our samples showed large magneto-resistance with a sharp switching between the high and low resistance states, which we assume corresponds to antiparallel and parallel alignment of the moments of these hybrid structures. The investigation of these promising hybrid structures is aimed at understanding the science of the new spin-based devices, laying the foundation for a new generation of ultra-fast, non-volatile electronics.